Modern Perl programs use several modules to enable additional features of Perl and of the CPAN.
Instead of copying and pasting all of these use lines,
instead write only one:

use Modern::Perl;

This enables the strict and warnings pragmas, as well as all of the features available in Perl 5.10. It also enables C3 method resolution order as documented in perldoc mro and loads IO::File and IO::Handle so that you may call methods on filehandles. In the future, it may include additional core modules and pragmas.

Because so much of this module's behavior uses lexically scoped pragmas, you may disable these pragmas within an inner scope with:

For forward compatibility, I recommend you specify a year as the single optional import tag. For example:

use Modern::Perl '2009';
use Modern::Perl '2010';

... both enable 5.10 features, while:

use Modern::Perl '2011';

... enables 5.12 features:

use Modern::Perl '2012';

... enables 5.14 features:

use Modern::Perl '2013';

... enables 5.16 features, and:

use Modern::Perl '2014';

... enables 5.18 features, and:

use Modern::Perl '2015';

... enables 5.20 features.

Obviously you cannot use newer features on earlier versions. Perl will throw the appropriate exception if you try.

By mid-2014, this module will drop support for 5.10 and 5.12 and will complain (once per process) if you use a year too old. As of January 2014, Perl 5.14 is unsupported by the Perl 5 Porters, so please consider upgrading.